Margot Robbie's Nutritionist on the #1 Thing People Get Wrong About Weight Loss

If there was an agreed-upon formula for weight loss, it would be to consume fewer calories than you burn. But as Dana James, Columbia-educated functional nutritionist, food coach, and nutritional therapist, writes for MindBodyGreen, it's a bit more complicated than that. In fact, James believes that's what most people get wrong about weight loss; far more factors influence your body's ability to maintain a healthy weight than simply eating right and working out.

"Weight loss is complex. It's not just food and exercise. The presiding equation of 'calories in, calories out' is woefully inadequate," writes James, whose former client was Margot Robbie. "Other factors, such as hormones, sleep, inflammation, the gut microbiome, medication, unexpressed emotions, and genes all influence your ability to lose weight and keep it off."

Her revised equation for weight loss follows this more detail-oriented philosophy: change in body fat = food + movement + hormones + sleep + gut microbiome + inflammation + medication + unexpressed emotions + genes. Though I was overwhelmed upon reading this lengthy formula, James argues that it's actually empowering: "You have the ability to influence all of these factors, except your genes," he says, which "play the weakest role in the equation because of how your environment interacts with them."

In short, thyroid hormones in addition to insulin, estrogen, and cortisol all affect weight gain and loss. Sleep, or a lack thereof, can increase hunger and food intake. Poor gut health and an off-kilter balance of good and bad gut bacteria can slow your body's ability to lose weight. By extension, chronic inflammation as caused by food sensitivities, mercury intake, and poor gut health can also lead to weight gain, as can certain medications like antidepressants. Finally, unexpressed emotions can lead to an unhealthy relationship with food, in addition to causing your body to hold on to excess weight. "Identify the most likely reason from this list and get to work on it," advises James. "Sustainable weight loss isn't always easy, but it's far better than … feeling hopeless about your weight."